Download Unit 3 – Atomic Theory Test Review

Name ___A. Sherman_____________ Period ________ Date ____________ Test Date:
Unit 1A – Atomic Theory Test Review ANSWERS
Below are the Atomic models of 5 scientists in the order of their discovery. Give the scientist name and their
discovery or theory. (Be sure to remember the order of these models)
1
2
3
4
5
Scientist
Democritus/Aristotle ___J.J Thomson___ _Ernest Rutherford__ ___Niels Bohr____ __Erwin Schrodinger_
Discovery / Theory
* plum-pudding model
*planetary model
*Ideas of “atomos”
meaning uncuttable
*cathode-ray experiment
*gold-foil experiment
*Bohr’s Model
*Quantum Model
*discovered electrons *discovered the nucleus *electron energy levels * location of e-__
6) Who first suggested the idea of an atom? Democritus had ideas(400BC), Dalton developed the first theory(1809)
7) Rutherford used the gold foil experiment. He found that most particles directed at the foil went straight
through, however very few were deflected back. What did this scientist conclude about the atom’s structure?
Rutherford concluded that the atom was mostly empty space, except for a small dense positively charged nucleus.
Fill in the following paragraph using the words below. Words can be used more than once.
Proton
Neutron
Electron
Nucleus
Mass Number
Atomic Number
The mass of an atom is contained mainly in its (8)___nucleus____ which contains (9)_____protons____ and
(10)___ neutrons____. The identity of an element is determined by its number of (11)___ protons___ which is the same
as its (12)____atomic number_____. The sum of an atom’s protons and neutrons is known as the atom’s
(13)___ mass number_____. Isotopes are atoms with the same number of (14)__ protons______ and different number of
(15)__neutrons____, causing them to have different (16)_____mass numbers_________. Ions are atoms with the same
number of (17)__ protons___ and different number of (18)_____ electrons____. The charge of an atom or ion is
determined by its number of (19)_____electrons___.
20) Label the following parts of the Nuclear Symbol of an Isotope / Ion
____Mass Number____________ 
24
________Atomic Number_______ 
11
21)
Na
+1
 ___Charge _ *positive means lost e*negative means gained e-
Use symbol above. How many protons? __11_ How many neutrons? _13__ How many electrons? _12_
22)
Tungsten – 152 has __74_ protons, __78__ neutrons and a mass number of __152___.
23)
A neutral Zirconium atom has _40__ protons and __40__ electrons.
24) How is mass number calculated? __protons PLUS neutrons___. Is it on the periodic table? _No__
Subatomic Particles in Neutral Atoms and Ions
Isotope Name
25)Strontium- 114
Symbol
Atomic
Number
Mass
Number
# of
Protons
# of
Neutrons
# of
Electrons
114Sr
38
114
38
76
38
26) Gold - 194
194
Au
79
194
79
115
79
27) Radon- 184
184 Rn
86
184
86
98
86
28) Sodium- 20
20Na
11
20
11
9
11
95
204
95
109
95
29) Americum- 204
204Am
30) Bismuth - 209
209 Bi3-
83
209
83
126
86
31) Actinium- 227
227Ac1-
89
227
89
138
90
276 Mt 1+
109
276
109
167
108
Ca2-
20
40
20
20
22
184 W 2+
74
184
74
110
72
32) Meitnerium- 276
33) Calcium- 40
34) Tungsten- 184
Average Atomic Mass **will not appear on the Test Sept 21/22, 2016
But SigFigs WILL
Significant Figures- Answers in the box below
35) For the following numbers, write the correct number of significant figures on the line.
4030 ___
5.0 ____
6x10-3___
2700 ___
9.80 ___
0.002 ___
0.30 ___
36) For the following calculations, show your answer with the correct significant figures.
6.0+3.21 = ________
20 x 5.26 = ________
50.0/ 25 = ________
Matching
___a__ The sum (addition) of protons and the neutrons.
___e__ An atom that loses or gains electrons.
___b__ Number of protons in an atom.
78.9- 2.45 = _______
A) mass number
B) atomic number
C) isotope
D) proton
E) Ion
____c__ An atom of the same element with a different mass number.
____d__ This subatomic particle identifies the element.
Significant Figures ANSWERS
35) For the following numbers, write the correct number of significant figures on the line.
4030 _3_
5.0 _2_
6x10-3_1_
2700 _2_
9.80 _3_
0.002 _1_
0.30 _2_
36) For the following calculations, show your answer with the correct significant figures.
6.0+3.21 = __9.2__
20 x 5.26 = __100__
50.0/ 25 = __2.0__
78.9- 2.45 =
__76.5__